1. Field of the Invention
The present invention relates to a tie and tie method for binding together adjacent support elements, and particularly to ties and methods for binding together reinforcing bars (rebar) in reinforced concrete construction.
Rebar improves the tensile strength and impact resistance of concrete, minimizes crack separation, and provides localized reinforcement and other improvements well known in the art. Accurate placement and positioning of the rebar is essential to achieve successful results.
2. Description of the Prior Art
Sections of rebar are typically arranged and tied together with lengths of wire to form a reinforcing structure or cage into and around which concrete is poured to form the reinforced concrete structure. In this process the initially tied portions must be tied securely enough to maintain their particular orientation and assembled positions during subsequent tying of the remaining portions by workers stepping on and clambering over the structure.
The process of looping wire around adjacent sections of rebar takes considerable skill, is labor intensive and tiring. If not done properly, a reinforced structure formed of tied rebar can collapse and cause considerable damage and injury to workers.
Various methods and power tools have been developed to aid in tying rebar. For example, U.S. Pat. No. 1,512,763 (Homgreen) describes a wire clip to connect crossed rebars in a diagonal manner. U.S. Pat. No. 1,185,263 relates to a spring clip to tie together crossed rebars. U.S. Pat. No. 3,169,559 (Working) discloses a wire tying tool to apply U-shaped wires over crossed rebars. U.S. Pat. No. 3,234,616 (Wantland) relates to looped wire ring fasteners. U.S. Pat. No. 3,302,348 (Pratt) describes a wire hanger system to hold rebar in place in prestressed concrete beams. U.S. Pat. No. 3,786,841 (Albrecht et al) discloses special tools for twisting and tying a wire. U.S. Pat. No. 4,388,791 (Anderson) describes a spring wire clip that is snapped over crossed rebars. U.S. Pat. No. 4,798,231 (Glaus et al) relates to a wire clamp and tool to apply it. U.S. Pat. No. 5,431,196 (Forrester et al) describes a power tool for applying wire from a feed to intersecting rebar. U.S. Pat. No. 5,913,341 (Jones) describes a geared tying device to apply wire bundling around rebar, and U.S. Pat. No. 6,128,882 (Jones) describes a hooked spring wire that ties together two pieces of rebar.
None of these devices or methods meet important needs or requirements of the reinforced concrete industry, particularly the need for a strong non-wire tie that can be quickly applied, is removable, and is capable of developing symmetric forces that will not warp or unbalance the tied cage structure and cause instability prior to and during the pouring of concrete.